<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<script>
			var age=18;
			age="hello";
			age=true;
			//alert(age);
			//alert(typeof age);
			var bisdfa;
			//alert(typeof bisdfa);
			
			//var username=null;
			//alert(typeof username);
			
			var s=new String();
			alert(typeof s);
		</script>
	</head>
	<body>
	</body>
</html>
